In terms of flight training organisations there are none as far as I am aware. MSF finished last year and JD training moved to Liverpool. The only other business operator is Ocean Sky who look after the majority of business jets. To be honest, being an employee at Manchester Airport myself it doesn't really seem the place for voluntary work. I recommend joining the RAF Air Training Corp and getting some free flying, but you may be a little old to be a cadet. You could always look up your nearest squadron and ask.